Jet's java.util.stream
implementation will automatically convert a
stream into a DAG
when one of the terminal methods are called. The DAG
creation is done lazily, and only if a terminal method is called.
The following DAG will be compiled as follows:
IStreamMap<String, Integer> ints = jet.getMap("ints");
int result = ints.stream().map(Entry::getValue)
.reduce(0, (l, r) -> l + r);